Thanks, Chris.
Yeah, we found the answer: CMC FD faders don’t work (they skip over VCA faders), but the fader on the CMC CH module does work.
I consider that good news.
(Also, the CMC FD’s LEDs do respond as one would expect if they’re controlled from a VCA fader, so no issue there.)
Good point about the Nuage.
Btw, I do think the CMC is based on HUI / Mackie if not 100% to spec.